From Halopedia, the Halo wiki
Personally it's either the fear and dread that takes over when Floodgate starts, or when One Final Effort starts playing on The Covenant near the later part of the mission.
The fight between The Chief and Locke, would've ended with Locke either dead or barely alive if it were an accurate portrayal.
I know my Gamertag is a bit confusing considering my name is TheLoneOne0303, yet it's The Lone One294 on Xbox, my bad though. And yes I do realize my name is pretty edgy, not really much of an edgy person. It just happened to be a name I came up with as my 12 year old self and decided to just stick with it.